Stem valve stopper

ABSTRACT

A stem valve stopper that has a shell ( 1 ) intended to be mounted to a faucet (K). An operating stem ( 8 ) is mounted for rotation but is axially fixed in the stopper shell ( 1 ) and has a lower end that acts as a valve seat surface ( 12 ). The stem  8  has an interior section ( 7 ) that is threadably engaged with a mobile fitting ( 6 ) that is mounted in the shell so that it can be moved axially but cannot be turned or rotated inside the stopper shell. The mobile fitting ( 6 ) has an annular lower end surrounding a valve seat ( 12 ). A valve sealing member ( 17 ) made from elastomeric material is mounted in the lower end of stopper shell ( 1 ) and is spring biased downstream toward the valve seat ( 12 ). The mobile fitting ( 6 ) can be operated to push the sealing member ( 17 ) upstream away from valve seat surface ( 12 ) and provide flow about the valve seat ( 12 ). The valve seat is made from elastomeric material and preferably inside its retaining regions has a hollow space so that, in the closed mode, it is dilated by the pressure of the water to press against the valve seat surface ( 12 ).

TECHNICAL FIELD

This invention relates to a stopper of the rotating screw type, intendedto be applied to a cock, tap or faucet to adjust the flow of waterbetween an intake passage and an outlet passage.

BACKGROUND OF THE INVENTION

Rotating screw stoppers have long been used to control the flow througha tap or faucet. The screw has an exterior end mounted to a handle. Thescrew, commonly in the form of a stem or arbor, is threadably engaged toa housing and mounting a mobile valve seal or washer at the interiorend.

As the screw valve is tightened, the washer is compressed against avalve seat. However, the washer by being rotated as it compressedagainst the valve seat until the stem was fully tightened unduly woreboth the washer and the valve seat. While the washer could be replaced,the valve seat could not. Furthermore, the stem rose out of the housingas the valve was opened which many users deemed undesirable. Non-risingstem valves have been developed that use shearing action of a valveseal. However, compressive valves are often still desirable due to thebetter sealing seating available through compressive action. Morenon-rising stem valves have been developed that continue to usecompressive action of the seal against a fixed valve seat.

A non-rising stem stopper essentially compresses a shell, intended to beaffixed securely to the body of a faucet device. A mobile fitting ismounted in an axially movable manner and in a nonrotatable manner insidethe shell of the stopper and bearing a valve seal. An operating stem ismounted for rotation and fixed in an axial direction in the shell o thestopper. The stem has one end inside the shell, linked by a screwthreading to the mobile fitting, and an outer end that protrudes formthe shell of the stopper and constructed to mount an operating handle.Rotation of the handle causes axial shifting of the mobile fitting andthe valve seal which, cooperating in a timely fashion with a valve seatplaced between the intake passage and the outlet passage of the body ofa faucet valve brings about the desired adjustment of the water flow.

Traditionally, the valve seal, supported by the mobile fitting, was madeup of a packing disc consisting of elastomeric material. The mount ofthe inlet passage is formed in the body of a faucet, itself as a valveseat that cooperates with the packing disc to adjust the flow. Anexample of this traditional arrangement is provided in document DE-U-9418 554.

With this arrangement, a sealing washer made of elastomeric material wassubject to deterioration. After deterioration, the washer can be easilyremoved by dismantling the shell of the stopper form the body of the setof cocks, taps and valves. Furthermore, the repair was inexpensive. Asimple washer with a central hole was attached via a bolt.

However, the valve seat that cooperates with this washer is alsosubjected to deterioration. Due to the valve seat being a part of thebody of a cock, tap or valve, it can be restored only by working on itwith a suitable manual milling machine. Such a repair is not an easyoperation nor are the results always satisfactory and the repair cannotbe repeated more than several times.

An attempt was therefore undertaken to make this valve seat on aseparate member that is screwed into the body of the faucet and that canbe extracted so that it may be repaired or replaced. Such a modificationresults in an excessive increase in the cost of the faucet.

Furthermore, the operations involved in disassembly and reassembling theapplied valve seat are not easy and require special tools.

An attempt was made to remedy this inconvenience, for example, asdisclosed in document EP-B-O 606 419. In this disclosure, the valve sealis a rigid element forming a part of the mobile fitting of the stopper.A special packing made of elastomeric material installed in the shellitself fits tightly against the mount of the intake passage presented bythe body of a faucet and which, will cooperate with the rigid vale sealpresented by the mobile fitting of the stopper. The body of the faucetis thus protected against any deterioration; but the special necessarypacking must have a complex configuration and is therefore expensive.The shell of the stopper also requires relatively expensive processingto manufacture a seat intended to receive such a packing.

According to International Patent Application WO 93/24774, the use of apacking with a complex shape was avoided by installing a first ferrulethat forms a ring-shaped shoulder in the end of the body of the stopperwith the stop bolt. A second ferrule is installed inside the first onethat received a static packing intended to provide a seal against themouth of the inlet passage of the faucet body. The interior end of thesecond ferrule holds an elastomeric retaining sealing member by a springtoward the shoulder of the first ferrule. The mobile fitting of thestopper moves axially onto the sealing element for shutting off flowsand rises away from the sealing element to an open position. Adisadvantage of this arrangement is that two ferrules must be used.Besides the added costs and complexity of two ferrules, the presence oftwo ferrules adds thickness inside the shell of the stopper. Thisincreased thickness limits the diameter of the elastomeric sealingmember and the passage therethrough which in turn restricts the maximumflow volume of the stopper under maximum opening conditions.

Furthermore, in the known stopper constructions, the pressure of thewater works on the mobile fitting over a large cross section, givingrise to a relatively powerful force that must be overcome by working thestopper. Furthermore, as the elastomeric sealing member wears out or iscrushed, the mobile fitting axially advance an increased distanceposition to provide the seal in the closed position in turn whichentails inconveniences and interferes with the service life of thepacking. In addition, the known valve stopper has static packings placedbetween the shell of the stopper which can yield only to a very limiteddegree. The distance between the region in which the valve stopper shellis screwed onto the faucet body and the surface of the body againstwhich said static packing must establish a successful seal becomescritical. In some cases, manufacturing here requires compliance withexcessively restricted tolerances, which again causes higher costs andgives rise to the possibility of inconveniences due to the heatexpansion of the parts.

What is needed is a valve stopper with a non-rising stem so as to besealed against the body of the faucet with the use of a simply shapedpacking and without any need for expensive work on the shell of thestopper. It is further needed to have a packing and that can be easilyaccessed and replaced when it has worn out or is broken. What is alsodesired is to increase maximum flow rates of a valve stopper for a givenouter dimension and to decrease the total force due to the waterpressure against the mobile fitting to reduce the force needed tooperate the valve stem. It is also desired to incorporate a device toreduce the noise level connected with any severely restricted flow ofwater.

It is further desirable to construct such a stopper that may haveincreased manufacturing tolerances as to the distance between the regionin which the stopper is installed in the faucet body and the surface ofthe body where the seal must be established with the packing seal.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a valve stopper includesa shell constructed to be sealingly securable to a faucet body. Anoperating arbor is mounted rotatably in the shell of the stopper. Anouter end of the arbor protrudes from the shell of the stopper andconstructed to mount an operating handle. The arbor has an inner endforming a valve seat surface. Preferably the arbor is mounted only forrotatable motion and is fixed in an axial direction in the shell.

A mobile fitting is mounted in an axially movable fashion inside theshell of the stopper and operably connected with the arbor to moveaxially as the arbor rotates. The mobile fitting has the shape of anannular jacket surrounding the arbor with radial ports therethrough andcan move upstream from the valve seat surface. The annular mobilefitting is preferably non-rotatably fixed with respect to the shell andthreadably engaged to the arbor for only axial movement in the shell asthe arbor is rotated.

A first annular sealing member cooperates with the valve seat surface onthe arbor at one axial end to shut off the valve stopper and constructedto abut against the annular mobile fitting. As the mobile fittingaxially moves in the shell upstream toward an open position, the sealingmember is moved away from the arbor and unseated from the valve seatsurface. The sealing member is resiliently biased to move downstreamtoward and abut the valve seat surface as the mobile fitting is axiallymoved toward a closed position.

Preferably the first annular sealing member is housed in a singleferrule. The ferrule has a support seat for seating a biased sealingelement and a second seat for seating a static sealing element toprovide a sealing connection about a mouth of a passage in the body ofthe faucet to the inlet in the valve stopper.

In one embodiment, the static sealing element is provided by a secondannular sealing member biased in a direction opposite to the bias of thefirst annular sealing member. Both the first and second annular sealingmember are received directly in one end of the shell of the stopper andsealingly abut an inner surface of said shell. Each sealing member ispreferably made from elastomeric material biased by a spring. Preferablya single biasing element applies the resilient bias to both the firstand second sealing members in opposite directions. In anotherembodiment, the sealing members are made from rigid material and biasedby a spring and provided with a retaining packing. In anotherembodiment, the sealing members are made from elastomeric material andbiased by their own resilient elasticity.

It is desirable that the radial ports in the mobile fitting haverespective narrowed passage sections which receive flow under conditionsof severe choking. The narrow passages are formed by one of protrusionssituated in said radial ports, millings, and small holes in a wall ofthe mobile fitting.

In accordance with another aspect of the invention, the operating arboris mounted rotatably in the shell of the stopper. The mobile fitting ismounted in an axially movable fashion inside the shell of the stopperand operably connected with the arbor to move axially as the arborrotates. An interior valve seating surface is axially affixed in theinterior of the shell. The mobile fitting has the shape of an annularjacket surrounding the interior valve seat surface with radial passagestherethrough. The annular sealing member is operably connected to aninlet for allowing flow therethrough and has its downstream endsealingly abutted to the valve seating surface. The annular mobilefitting can move the sealing member upstream away from the valve seatingsurface as it is axially moved to an open position. The sealing memberis resiliently biased to move downstream toward and abut the interiorvalve seat surface as said mobile fitting is axially moved toward aclosed position.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference now is made to the accompanying drawings in which:

FIG. 1 is a side elevational and segmented view of a valve stopperaccording to a first embodiment of the invention in the closed position;

FIG. 2 is a view similar to FIG. 1 illustrating the valve stopper in theopen position;

FIG. 3 shows an enlarged detail looking along lines 3—3 in FIG. 2;

FIG. 4 is a view similar to FIG. 1 illustrating a second embodiment inthe closed position;

FIG. 5 is a view similar to FIG. 4 illustrating the second embodiment ofthe invention in the open position;

FIG. 6 is a view similar to FIG. 1 illustrating a third embodiment inthe closed position;

FIG. 7 is a view similar to FIG. 6 illustrating the third embodiment inthe open position; and

FIG. 8 is a cross sectional view taken along lines 8—8 in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, a valve stopper has a shell 1 provided with anexterior screw threading 2 for its connection to the body of a faucet(of which the drawing for reasons of clarity only shows the regionpresenting mouth K of passage P for water intake). The stopper also hasperipheral openings 3 for the discharge of water, and a packing 4 tocreate a tight hold with the body of the faucet. The shell 1 houses amobile fitting 6 mounted via a splined connection 11 so as to benon-rotatably movable in the axial direction. A packing 5 establishesthe seal between shell 1 and mobile fitting 6. In shell 1, there is alsohoused an operating stem or arbor 9. The stem 9 is mounted for rotationbut is affixed in the axial direction. Stem 9 has a threaded internalsection 7 that is screwed into a corresponding screw threading 24 ofmobile fitting 6 and has an outer end 8 that protrudes from shell 1 andis so arranged as to receive an operating handle (not shown). All of theparts described to far are commonly found in a variety of stem valvesand are well known. When operating stem 9 is rotated by means of ahandle, the mobile fitting 6 is shifted axially up and down.

In contrast to known designs, stem 9 extends into the inside of thestopper beyond threaded part 7 to form a valve seat 12, and a sealinggasket 13 establishes its seal with respect to mobile fitting 6. Inturn, mobile fitting 6 has the shape of an annular jacket and extendsaround piston 12, presenting radial delivery openings 14.

As illustrated in FIGS. 1 and 2, a ferrule 10 made of rigid material isinstalled in the end of body 1, which is opposite stem 9, there isinstalled in a fixed manner. The ferrule has a substantially cylindricaldownstream end facing toward the inside of the stopper and an outsideflange 15 that forms a seat for a static packing 16 that is intended toprovide a seal against mouth or nozzle K of passage P for the intake ofwater from the faucet body. A passage 25 passes through ferrule 10.

An elastomeric annular sealing member 17 is mounted for axial movementin ferrule 10 and which is resiliently biased toward valve seat 12 by aspring 18 which rests against flange 15 of ferrule 10. The stackedthickness of body 1 and of the single ferrule 10 limits the diameter ofannular sealing member 17. The annular sealing member 17 can be sized tospan the entire inner diameter of the ferrule 10 and have a sizedaperture 26 outside will permit a strong flow volume (in the maximumopen position as described later).

When the mobile fitting 6 is in the position shown in FIG. 1, that is,in the closed position that is most distant from inlet 25, lifted off ofsealing member 17, and lifted above valve seat 12; sealing member 17 isbiased by spring 18 and will sealingly abut against valve seat 12. Thestopper is therefore in the shut-off or closed position. In thisposition, the water pressure, acts on the cross-sectional exposed areaof sealing member 17 which may exceed the exposed surface area of valveseat 12 thus contributing to maintaining the closure with a force inproportion to the water pressure at passage P.

The valve stem 9, as it rotates, can shift mobile fitting 6 towardsealing member 17 as shown in FIG. 2. Consequently, the mobile fitting 6will come to rest against the peripheral annular region of sealingmember 17 and will push it away from valve seat surface 12. The watercomes from inlet passage P through mouth K which is sealed with packing16. The water then passes through the lower passage 25 in ferrule 10 andthrough the passage 26 in sealing member 17 and then between member 17and valve seat 12. The water flows through delivery openings 14 ofmobile fitting 6 and finally comes out of shell 1 through its peripheralopenings 3 and is passed back into the faucet body in order then to bedelivered by it through a spout, showerhead or other nozzle device. Thepermitted flow volume naturally depends on the distance that the mobilefitting 6 has shifted sealing member 17 from valve seat 12. The flowrate can be adjusted up to a predetermined maximum by rotation of stem9.

The operation of this stopper offers various advantages, in addition toits structural advantages. The fact that sealing member 17 is shiftedduring normal operation of the faucet and, hence, frequently, andprovides dynamic movement rather than a mere static function thuspreventing deposits of limestone between member 17 and its seat, ferrule10 which can seriously impair successful operation of the valve. Thefact that the mobile fitting when moved to press against the elastomericmember 17 is opening the stopper and not, as is customary, closing it isalso advantageous. In this way, the stopper remains entirely protectedagainst the possibility, which often happens in known stoppers, that theuser might close the stopper with excessive force, which can damage theseals. Furthermore, the fact that valve seat surface 12 rotates withoperating stem 9 means that it will periodically exert a polishingaction on sealing member 17 further preventing the formation oflimestone deposits and expelling any possible small, foreign bodies.

The described structure is particularly suitable for the introduction ofvery simple device that can reduce the flow noise which tends to beconsiderable under conditions of severe restriction which exist at thebeginning of the opening and at the end of the closing action. Littleteeth or protrusions 20 as clearly shown in FIG. 3 protrude on one sideof the delivery openings 14 form narrow passages therebetween.Alternately grills situated in the delivery openings or from millings orsmall holes made in a wall of the mobile can suffice. Under conditionsof severe choking, the flow must thus pass through these narrowpassages, causing the flow to slow down and moderate its turbulence andhence its noise level. FIGS. 4 and 5 illustrate another embodiment thatavoids the critical nature of the distance between the region in whichthe valve stopper is screwed into the body of the faucet and the mountsurface K of the body of the faucet against which the packing seal mustsealingly abut. In these figures and the following figures, the sameparts or parts corresponding to those already described for the firstembodiment have the same reference numbers and are not described anyfurther.

In this embodiment the ferrule 10 is eliminated as in the firstembodiment, and sealing member 17 is received in the end of the shell 1of the stopper. For this reason, the sealing member 17 in the secondembodiment may have an enlarged diameter than the sealing member 17 inthe first embodiment, thus allowing an increased maximum flow. There isalso provided a second sealing member 19, arranged in an upside-downposition with respect to the first sealing member 17 and which canadvantageously be biased by the same spring 18 in an opposite directionfrom sealing member 17. Sealing member 19 thus tends to bias itself outfrom body 1 of the stopper, and against the body of a faucet to providea seal against mouth K about intake passage P. In this case, likewise,as in the case of member 17, the seal is established both by the forceof the spring 18 and by the pressure of the water, which acts on theinternal surface of sealing member 19. Therefore, the seal isestablished with a force that is in proportion to the water pressure andhence in a particularly secure fashion.

Because sealing member 19 can axially move in body 1 of the stopper, itcan accommodate even major differences in distance D. which iseffectively present between the region between shoulder S in which thestopper is screwed into the body of the faucet and valves and mouthsurface K of the faucet body against which the seal must be establishedwith member 19. This feature also facilitates and allows the valvestopper according to the invention to replace preceding stoppers infaucets and valves in which the distance D can have some varying values.

It is also noted that the effect of the inevitable heat expansions ofthe parts, which in known design harms the performance of the staticpacking 16 arranged between the stopper and the faucet body. In thisembodiment, the expansion provides an advantageous feature. The repeatedexpansion produces repeated small movements of sealing member 17 in body1 of the stopper and thus, by virtue of this effect, also prevents theformation of harmful deposits of limestone. Furthermore, this embodimentallows the sealing members 17,19 to be easily exchanged when they areworn out or damaged by simply unthreading the stopper from body 1 of thestopper and replacing new collars without requiring the use of anytools.

A third embodiment is disclosed in FIGS. 6-8. In this embodiment thevalve seat 12 is not part of the stem 9 but is a cap member 32 securedto the top end of ferrule 10. It may be press fitted or attached via abayonet or other secure fitting method about its periphery 33. The valveseat 12 is secured in place via radially extending braces 34 extendingfrom seat 12 to periphery 33. Radial vents 35 surround seat 12 betweenbraces 34 as shown in FIG. 8. The mobile fitting 11 hascircumferentially positioned fingers 36 extending through some of thevents 35. Radial openings 14 are formed between the fingers 36. Thesealing member 17 in this embodiment is made from a rigid material suchas ceramic and has a sealing gasket 38 about its periphery abutting theupper surface of ferrule 10.

As shown in FIG. 6, when the mobile fitting 6 is lifted, the sealingmember 17 is biased to seal against fixed valve seat 12. As mobilefitting 6 is axially moved downward in the upstream direction, as shownin FIG. 7, the fingers 36 extend through some of the vents 35 and pushthe sealing member 17 away from fixed valve seat 12. As sealing member17 moves upstream and away, the water flow passes through vents 35 aboutvalve seat 12 and out through openings 14 and outlets 3.

The stem valve stopper according to the invention thus can attain all ora part of the above stated advantages without any significant increasein its production cost. In particular, the designer can in an optimumfashion adapt the features of the stopper to any special requirementsassociated with each particular application.

It must be understood that the invention is not restricted to theembodiments described and illustrated by way of example. Somemodifications are within the reach of the technician in the field,especially as regards the structure of the sealing member where it canbe pushed by its own elasticity. In this latter case, it is alsopossible to make two sealing members all in one integrated piece with asingle intermediate region, for example, in the form of bellows, actingas elastic member for both. Arrangements intended to silence the flow ofthe stopper can also be varied and, where a second sealing member isused to work against a surface of the set of taps and valves, one mayadopt arrangements to prevent the members 17 and 19 from coming outcompletely, except when they must be replaced.

Other variations are foreseen without departing from the spirit andscope of the invention as defined in the appended claims.

I claim:
 1. A valve stopper includes a shell constructed to be sealinglysecurable to a faucet body; an operating arbor mounted rotatably in saidshell of the stopper a mobile fitting mounted in an axially movablefashion inside said shell of the stopper and operably connected withsaid arbor to move axially as said arbor rotates; and an outer end ofsaid arbor protruding from the shell of the stopper and constructed tomount an operating handle, said valve stopper characterized by: saidarbor having an inner end forming a valve seat surface; said mobilefitting having the shape of an annular jacket with radial portstherethrough; a first annular sealing member cooperating with the valveseat surface on said arbor at one axial end, constructed to abut againstthe annular mobile fitting, being movable away from said arbor by saidmobile fitting as said annular sealing surface is axially moved to anopen position, and resiliently biased to move toward said valve seatsurface as said mobile fitting is moved toward a closed position.
 2. Avalve stopper as defined in claim 1 further characterized by: saidoperative arbor mounted only for rotatable motion and fixed in an axialdirection in said shell; said annular mobile fitting is non-rotatablyfixed in said shell and threadably engaged to said arbor for axialmovement as said arbor is rotated.
 3. A valve stopper as defined inclaim 2 further characterized by: said first annular sealing member ishoused in a single ferrule, said ferrule having a support seat forseating a bias element and seating a static sealing element to provide aseal about a mouth of an inlet passage in the body of the faucet.
 4. Avalve stopper as defined in claim 2 further characterized by: a secondannular sealing member biased in a direction opposite to the bias of thefirst annular sealing member to provide a static seal about a mouth ofan inlet passage in the body of the faucet.
 5. A valve stopper asdefined in claim 4 further characterized by: a single biasing elementapplying the resilient bias to both first and second sealing members inopposite directions.
 6. A valve stopper as defined in claim 5, furthercharacterized by: both first and second annular sealing members beingreceived directly in one end of the shell of the stopper and sealinglyabutting an inner surface of said shell.
 7. A valve stopper as definedin claim 4, further characterized by: said sealing members being madefrom elastomeric material biased by a spring.
 8. A valve stopper asdefined in claim 4, further characterized by: said sealing members beingmade from rigid material and biased by a spring and provided with aretaining packing.
 9. A valve stopper as defined in claim 4, furthercharacterized by: said sealing members being made from elastomericmaterial and biased by their own resilient elasticity.
 10. A valvestopper as defined in claim 9, further characterized by: the two sealingmembers being integrally formed from elastomeric material, with anintermediate interposed biasing section therebetween that biases bothsealing members in said opposite directions.
 11. A valve stopper asdefined in claim 1, further characterized by: the radial ports of saidmobile fitting have respective narrowed passage sections which receiveflow under conditions of severe choking.
 12. A valve stopper as definedin claim 11 further characterized by: said narrow passages are formed byone of protrusions situated in said delivery openings, millings, andsmall holes in a wall of the mobile fitting.
 13. A valve stopper asdefined in claim 1 further characterized by: a second annular sealingmember biased in a direction opposite to the bias of the first annularsealing member to provide a static seal about a mouth of an inletpassage in the body of the faucet.
 14. A valve stopper as defined inclaim 13 further characterized by: a single biasing element applying theresilient bias to both first and second sealing members in oppositedirections.
 15. A valve stopper as defined in claim 14, furthercharacterized by: both first and second annular sealing members beingreceived directly in one end of the shell of the stopper and sealinglyabutting an inner surface of said shell.
 16. A valve stopper as definedin claim 13, further characterized by: said sealing members being madefrom elastomeric material biased by a spring.
 17. A valve stopper asdefined in claim 13, further characterized by: said sealing membersbeing made from rigid material and biased by a spring and provided witha retaining packing.
 18. A valve stopper as defined in claim 13, furthercharacterized by: said sealing members being formed from elastomericmaterial and biased by their own resilient elasticity.
 19. A valvestopper as defined in claim 18, further characterized by: the twosealing members being integrally formed from elastomeric material, withan intermediate biasing section interposed therebetween that biases bothsealing members in said opposite directions.
 20. A valve stopperincludes a shell constructed to be sealingly securable to a faucet body;an operating arbor mounted rotatably in said shell of the stopper, amobile fitting mounted in an axially movable fashion inside said shellof the stopper and operably connected with said arbor to move axially assaid arbor rotates; and an outer end of said arbor protruding from theshell of the stopper and constructed to mount an operating handle, saidvalve stopper characterized by: an interior valve seat surface axiallyaffixed in the interior of said shell; said mobile fitting having theshape of an annular jacket surrounding said interior valve seat surfacewith radial passages therethrough; and an annular sealing memberconstructed for allowing flow therethrough and having its downstream endcooperating with said valve seat surface; the annular mobile fittingabuttable against said annular sealing member to move said sealingmember upstream and away from said valve seating surface as the mobilefitting is axially moved upstream to an open position; and said sealingmember resiliently biased to move downstream toward and to abut saidvalve seat surface as said mobile fitting is axially moved downstreamtoward a closed position.
 21. A valve stopper as defined in claim 20further characterized by: said sealing member, slidably mounted in aferrule between said fixed interior axially affixed valve seat surfaceand a sealing gasket that seals said shell about an inlet mouth in saidshell.